The present invention relates to a magnetoresistive element for use in a displacement sensor, a contactless potentiometer and so forth and, more particularly, to a magnetoresistive element which is free from the influence of temperature variations and aging.
Magnetosensitive materials heretofore employed for magnetoresistive elements are defective in that their resistance-magnetic field characteristic is relatively seriously affected by temperature variations. In a magnetoresistive element proposed as a solution to this problem, a pair of magnetosensitive material parts having the same characteristics are aligned in their lengthwise direction and connected in series to each other; a voltage is applied across the series connection of the magnetoresistive parts; an output terminal is led out from their connection point; and a magnet is disposed in opposing relation to the magnetoresistive parts and moved in their lengthwise direction so that an area of one of the parts covered by the magnet may increase while at the same time an area of the other part covered by the magnet may decrease. In such an arrangement, however, in order to completely prevent the influence of temperature variations and aging, it is necessary so that the resistance-temperature coefficient and the aging coefficient of the magnetoresistive parts remain unchanged regardless of whether a magnetic field is applied to them or not. In general, however, these coefficients do not remain constant. For this reason, the conventional magnetoresistive elements have the drawback that they are subject to the influence of temperature variations and aging.